Water quality in rivers of western Switzerland: Application of an adaptable index based on benthic invertebrates

Water quality was estimated from 205 samples of benthic invertebrates collected between 1982 and 1986 in 51 rivers of western Switzerland (canton of Vaud). Each sample consisted of the combined list of taxa resulting from one spring sample pooled with one summer sample. Water quality was indicated by total number of taxa and number of taxa intolerant of pollution: i. e. Heptageniidae, Plecoptera, and Trichoptera with a case. Six classes of values were delimited for each of these two variables by cluster analysis. Values from zero to five were attributed to each class. The index of water quality was computed by adding these two values in each sample. According to this index, good water quality was indicated by 42% of samples. This index can be adapted to other rivers because its components are easily modified.     

Spatial–temporal variability in water quality and macro-invertebrate assemblages in the Upper Mara River basin,Kenya

Tropical rivers display profound temporal and spatial heterogeneity in terms of environmental conditions. This aspect needs to be considered when designing a monitoring program for water quality in rivers. Therefore, the physico-chemical composition and the nutrient loading of the Upper Mara River and its two main tributaries, the Amala and Nyangores were monitored. Initial daily, and later a weekly monitoring schedule for 4 months spanning through the wet and dry seasons was adopted. Benthic macro-invertebrates were also collected during the initial sampling to be used as indicators of water quality. The aim of the current study was to investigate the physico-chemical status and biological integrity of the Upper Mara River basin. This was achieved by examining trends in nutrient concentrations and analyzing the structure, diversity and abundance of benthic macro-invertebrates in relation to varying land use patterns. Sampling sites were selected based on catchment land use and the level of human disturbance, and using historical records of previous water quality studies. River water pH, dissolved oxygen, electrical conductivity (EC), temperature, and turbidity were determined in situ. All investigated parameters except iron and manganese had concentration values within allowable limits according to Kenyan and international standards for drinking water. The Amala tributary is more mineralized and also shows higher levels of pH and EC than water from the Nyangores tributary. The latter, however, has a higher variability in both the total phosphorus (TP) and total nitrogen (TN) concentrations. The variability in TP and TN concentrations increases downstream for both tributaries and is more pronounced for TN than for TP. Macro-invertebrate assemblages responded to the changes in land use and water quality in terms of community composition and diversity. The study recommends detailed continuous monitoring of the water quality at shorter time intervals and to identify key macro-invertebrate taxa that can be used to monitor changes of the water quality in rivers of the Mara basin as a result of anthropogenic changes.     

Multimetric Macroinvertebrate Index Flanders (MMIF) for biological assessment of rivers and lakes in Flanders (Belgium)

The European Water Framework Directive requires that member states assess all their surface waters based on a number of biological elements, including macroinvertebrates. Since 1989, the Flemish Environment Agency has been using the Belgian Biotic Index for assessing river water quality based on macroinvertebrates. Throughout the years, the Belgian Biotic Index has proven to be a reliable and robust method providing a good indication of general degradation of river water and habitat quality. Since the Belgian Biotic Index does not meet all the requirements of the Water Framework Directive, a new index, the Multimetric Macroinvertebrate Index Flanders (MMIF) for evaluating rivers and lakes was developed and tested. This index was developed in order to provide a general assessment of ecological deterioration caused by any kind of stressor, such as water pollution and habitat quality degradation. The MMIF is based on macroinvertebrate samples that are taken using the same sampling and identification procedure as the Belgian Biotic Index. The index calculation is a type-specific multimetric system based on five equally weighted metrics, which are taxa richness, number of Ephemeroptera, Plecoptera and Trichoptera taxa, number of other sensitive taxa, the Shannon-Wiener diversity index and the mean tolerance score. The final index value is expressed as an Ecological Quality Ratio ranging from zero for very bad ecological quality to one for very good ecological quality. The MMIF correlates positively with dissolved oxygen and negatively with Kjeldahl nitrogen, total nitrogen, ammonium, nitrite, total phosphorous, orthophosphate and biochemical and chemical oxygen demand. This new index is now being used by the Flemish Environment Agency as a standard method to report about the status of macroinvertebrates in rivers and lakes in Flanders within the context of the European Water Framework Directive.     

Empirical relationships between diversity of invertebrate communities and altitude in rivers: Application to biomonitoring

The relationships between the diversity of invertebrate communities and the altitude of sampling sites were analysed in 438 benthic samples, collected between 1982 and 1991, in 56 rivers of western Switzerland. Diversity, estimated from total number of taxa (genus or family) and from number of taxa intolerant of pollution, was positively correlated with increasing altitude. In contrast, density of human population and the level of organic pollution were negatively correlated with increasing altitude. Therefore, the upstream increase of invertebrate diversity was attributed to the decrease of human population which is the main source of organic pollution. In this study, altitude was used, instead of organic pollution, to predict diversity. Empirical relationships between diversity and altitude were applied to surveys of water quality to describe the general altitudinal pattern characteristic for each region and to single out anomalous sites and rivers. In addition, changes in the altitudinal patterns of diversity can be used to monitor the recovery of rivers from pollution.     

Trends in water quality variations in the Odra River the day before implementation of the Water Framework Directive

This paper contains an account of UN/EEC-sponsored research on water quality monitoring and assessments in the catchments areas of Europe's 10 transboundary rivers. In this context, water quality assessments established on the basis of monitoring data for Poland's rivers are discussed. Consideration is also given to the water quality assessment methods recommended by the EU Directives. The problem has been exemplified by the analysis of water quality variations in the transboundary river Odra in the time span of 1973–2003. For the years 1993–2003, the trends in water quality variations are calculated and the rates of variation are analysed. The points in time when the water quality will have attained the second class purity values are predicted, taking into account the requirements specified in Polish, Czech and German standards. Analysis of the trends in the variations of pollution parameters has revealed that the achievability of good water quality depends on the limit values adopted for the assessment.     

应用底栖动物完整性指数评价上海市河流健康

据2011-2013年对上海市31条河流底栖动物的调查结果,对31个生物参数进行分布范围、判别能力以及相关性等进行分析,确定构建上海市河流底栖动物完整性指数(B-IBI)的4个参数:(寡毛类动物+蛭纲)数量百分比、耐污类群分类单元数、双翅目数量百分比和集食者分类单元数百分比.采用比值法统一量纲,将各个生物参数分值加和得到上海市河流B-IBI值.利用构建的B-IBI对上海市31条河流健康状况进行评价,结果表明:31条河流中,有4条河流处于健康状态,8条河流处于亚健康状态,9条河流处于一般状态,8条河流处于较差状态,2条河流处于极差状态;远郊河流健康状态最好,近郊次之,市区最差.     

Benthic macroinvertebrates as indicators of the water quality in Bulgaria: A case-study in the Iskar river basin

Macroinvertebrates were sampled at 15 locations in the Iskar river basin in Bulgaria for the purpose of water quality assessment. Based on the chemical as well as the biological parameters, it was concluded that the water quality was still good upstream of Sofia, however, despite a huge waste water treatment plant, a strong decrease was observed when the river passed Sofia. Due to self-purification and dilution, a gradual amelioration of the water quality was observed 40 and 80 km downstream of Sofia, however, water quality was still insufficient. The Irish Biotic Index (IBI), which is currently used in Bulgaria for the national monitoring of macroinvertebrates for water quality assessment, does not fulfil the requirements of the European Union Water Framework Directive (WFD). The Multimetric Macroinvertebrate Index Flanders (MMIF), on the contrary, is a WFD compliant method developed for the northern part of Belgium, which is based on (1) the total number of taxa, (2) the number of Ephemeroptera, Plecoptera and Trichoptera taxa, (3) the number of other sensitive taxa, (4) the Shannon–Wiener index and (5) the mean tolerance score. The outcome of this MMIF was strongly correlated with the outcome of the Irish Biotic Index. Therefore, it should be possible to develop a similar multimetric index for macroinvertebrates to evaluate the biological water quality in Bulgaria without much effort.     

Development of a River Macrophyte Index (RMI) for assessing river ecological status

We present the process of developing a macrophyte based index (River Macrophyte Index – RMI) for assessing river ecological status, that would be applicable for rivers with moderate to high water alkalinity, flowing over low slope terrain. A reference value and boundary values were determined for five ecological classes. The relation between the developed index and two existing indices, the Reference Index (RI) and the Trophic Index of Macrophytes (TIM), and selected environmental variables was established. The RMI is based on species composition and abundance from 208 sampling sites being in reference or good hydromorphological conditions and differing in the catchment land use. The percentage of natural areas in the sub-catchment was used for classifying macrophyte taxa into 5 ecological groups. 65 plant taxa, of which 47 were identified as indicator taxa, were included in the analysis. To assess the ecological status of a river site, the presence of at least 3 indicator taxa is necessary, otherwise the assessment is considered inconclusive. RMI is expected to indicate multiple pressures on the river, including trophic level. The developed index and RI and TIM indices differed in relation to slope, distance to source and catchment size.     

An index to assess hydromorphological quality of Estonian surface waters based on macroinvertebrate taxonomic composition

We developed an index (MESH – Macroinvertebrates in Estonia: Score of Hydromorphology) to assess hydromorphological quality of Estonian surface waters based on macroinvertebrate taxonomic composition. The MESH is an average score based on the affinities of selected indicator taxa to flow velocity and bottom type. As both parameters were highly correlated (r = 0.65) indicator response to both parameters were combined. The list of MESH indicators includes 394 freshwater macroinvertebrate taxa derived from 3282 samples collected from rivers and lakes during 1985–2009. The indicators were selected out of 690 taxa, by applying the information-theoretical Kullback–Leibler divergence. The individual scores of macroinvertebrates range from 0 to 3, the higher scores indicating faster flow and/or solid bottom substrate. For standing waters, flow velocity was always considered zero. Among the reference waterbodies, mean MESH was the highest for small streams followed by middle streams, large streams, and lakes. In lakes with medium water hardness (the prevailing type in Estonia), the MESH decreased gradually from stony to muddy bottom. The highest MESH values for standing waters were observed in the stony surf zone of very large lakes (area > 100 km²). The lowest values occurred for small lakes with exceptional hydrochemical characteristics (soft- and darkwater, and calcareous types). Similarly, MESH indicated stream degradation by damming. Mean MESH in reservoirs with a muddy bottom was significantly lower than in reservoirs with a hard bottom, or in unregulated stream sections.     

Population dynamics of autotrophic picoplankton in relation to environmental factors in a productive lake

Spatial and seasonal fluctuations in autotrophic picoplankton (APP) abundance in a eutrophic, dimictic lake (Lake Aydat, France) were measured concurrently with a variety of environmental variables. Cell number ranged from 0.03 to 2.36×10⁶ cells·ml^–1 (highest concentrations were >5-fold higher than in oligotrophic lakes) and averaged 24 ± 7% of total picoplankton abundance (APP + heterotrophic bacteria). APP abundance (1) peaked in spring simultaneously with heterotrophic flagellate and ciliate densities, (2) decreased during the nitrogen-limited and summer stratification period, and (3) increased with fall turnover. In summer-autumn, the contribution of single-cell eukaryotic (up to 66%) and colonial prokaryotic (18%) forms to total abundance peaked in the bottom waters. Multivariate regression analyses suggest that >40% variance in APP number changes may be explained by ciliate abundance (at 0–4 m depth-range), heterotrophic flagellate number and oxygen concentration (5–9 m), and ciliate carbon biomass (10–14 m). The model accounting for changes in heterotrophic bacterial abundance (5–9 m) indicates chlorophylla concentration (r ²=58%) and ciliate abundance (r ²=34%) as dominant covariates. The data presented here suggest that micrograzers control APP abundance in Lake Aydat.     

Predicting river ecosystem response to glacial meltwater dynamics: a case study of quantitative water sourcing and glaciality index approaches

Glacier retreat and thinning are occurring in many regions of the world, leading to significant changes in river discharge, water quality and aquatic ecosystems. Therefore, it is increasingly necessary for environmental scientists and managers to develop and adopt methods that link changes in meltwater dynamics and biotic response to better understand and predict future ecosystem change in glacially influenced rivers. To this end, two approaches have been developed recently: (1) the ARISE quantitative meltwater contribution approach of Brown et al. (Freshw Biol 54:1357–1369, 2009b) and (2) the glaciality index (GI) of Ilg and Castella (Freshw Biol 51:840–853, 2006), which provides a measure of glacial runoff influence on stream ecosystems based on four environmental variables (water temperature, channel stability, electrical conductivity and suspended sediment concentration). However, the relative performance and potential complementarities of these two approaches have yet to be evaluated. We conducted a methodological comparison using detailed hydrological, water quality and biological datasets collected over two summers in the French Pyrénées. Analyses revealed strong and significant correlation between ARISE meltwater contributions and the GI. However, the ARISE approach performed better when differentiating glacial influence between streams and over time. Both approaches were significant predictors of macroinvertebrate taxonomic richness, beta diversity, the number of EPT genera and total abundance, although regression models were typically stronger for the ARISE meltwater contribution approach. At the species level, ARISE performed better for predicting the abundance of 13 of the 20 most common taxa. We propose both approaches are valuable for assessing the effects of decreasing meltwater contributions on river ecosystems at the community level but this case study suggests ARISE was better able to identify subtle differences in hydrological change, community response and the abundance of individual taxa. Comparative studies from other catchments are required to further evaluate the two methods.     

Development of guidelines for ammonia in estuarine and marine water systems

The water quality guideline trigger value for ammonia in estuarine and marine waters has been revised with the addition of 38 new results to the data set of 21 used in earlier guideline derivations. Using species sensitivity distributions, a new trigger value of 460 μg total NH₃-N/L was derived for slightly to moderately disturbed systems (95% protection concentration, PC95), with a value of 160 μg total NH₃-N/L applying to waters of high conservation value (PC99). For sediment pore waters, a guideline trigger value of 3.9 mg total NH₃-N/L, derived from the 80th percentile of background data from Sydney Harbour, is recommended. This value is likely to be exceeded in degraded sediments subject to dredging; however, ocean disposal of such sediments results in rapid decreases in porewater ammonia and a guideline trigger value for dissolved ammonia during disposal of dredged sediments of 1550 μg total NH₃-N/L is proposed.     

应用底栖动物完整性指数评价滇池流域入湖河流生态系统健康

采用底栖动物完整性指数(B-IBI)评价滇池流域入湖河流健康状况.根据滇池流域38个样点(9个参照点,29个干扰点)于2009年丰水期和2010年平水期采得的大型底栖动物数据,对19个生物参数进行分布范围、Spearman相关性和判别能力分析,确定构成滇池流域底栖动物生物完整性的指数为甲壳动物+软体动物分类单元数、集食者%、捕食者%和耐污类群%.用比值法统一量纲,计算各个生物参数的值,并将所得的值相加即得到B-IBI指数值.根据B-IBI指数值的25%分位数确定健康等级标准,并对小于25%分位数的值进行四等分,即得到滇池流域底栖动物完整性的评价标准,B-IBI>1.62为健康,1.03～1.62为亚健康,0.31～1.03为一般,0.10～0.31为较差,<0.10为极差.评价结果表明,滇池流域的38个样点中,16个为健康,5个为亚健康,6个为一般,6个为较差,5个为极差.B-IBI值与硝态氮和水温有较大的负相关关系,与其他理化因子相关性不明显.     

邛海入湖河流水质及其湖区响应特征(2011—2021年)

邛海是云贵高原水域面积>25 km²的11个天然湖泊之一。基于邛海入湖河流与湖区水质监测数据,揭示入湖河流水质特征,并探究其湖区响应。结果表明:2021年,邛海入湖河流水质空间异质性显著,且分为自然型、农业型和城镇型3种类型河流。官坝河等3条自然型河流水质优良,而高仓河等8条城镇型和农业型河流(R4～R11)水质较差,污染物浓度超标严重。2011—2021年,邛海主要入湖河流(官坝河、鹅掌河、小青河)的营养盐浓度呈下降或先增加后下降趋势,水质逐渐改善。流域土地利用变化是导致邛海入湖河流水质空间异质性的主要因素,同时也是河流水质在2011—2021年改善的原因之一。受湖泊水文环境与入湖河流污染类型影响,2017—2021年邛海湖区水环境及其与河流水质响应关系差异性明显:高枧湾水域(L5)水深浅、水环境容量小,主要受纳城镇污水,因而湖区营养盐与叶绿素a浓度高,在2021年达富营养状态;官坝河、鹅掌河与小青河入湖影响区(L1～L3)与小渔村(L4)水域湖水深、水环境容量大,污染物浓度与营养状态指数低,但因汇入的河流污染类型不同,湖区营养水平与河流水质响应存在季节性...     

Natural recolonization of a productive tropical pond: Day to day variations in the photosynthetic parameters

Chlorophyll pigments (CHL), primary productivity (PP) and particulate nitrogen (N_p) in relation to several environmental factors were monitored during planktonic colonization of an aquaculture pond (Layo, Côte d'Ivoire). How interactions between the organisms are established in an initially azoic environment were investigated. From March, 15 (D1) to March, 31 (D16), the system transformation went through three stages. First, a precolonization by heterotrophic microbial community from D1 to D2 (N_p < 1 m maximum at D2: 243 mg m^–2; CHL around 0). Then, a pioneer microalgal community developped from D3 to D7 (maximum CHL on D6: 19 mg m^–2; PP: 1.0 g C m^–2 d^–1) with a significant contribution of picoplankton (CHL and PP < 3 m: 33 and 23% of the total, respectively). Finally, a second microalgal colonization was noticed from D9 to D12 (maximum CHL: 55 mg m^–2, PP: 2.8 g C m^–2 d^–1), largely dominated by nanoplankton (CHL and PP > 3 m: 95 and 99% of the total, respectively). Overall, photosynthetic activity appeared to be closely linked to algal biomass. The study of autotrophic biomass and activity in different size classes in relation to the other parameters allowed us to precise the origin of the biomass fluctuations. The first bloom appeared to be controlled by selective grazing on small algae. The second algal development ended when N requirement represented at least 69% of N supply (in the N — NH₄ form). This control was enhanced by the appearance of rotifers, leading to a more complex equilibrium.     

Dissolved organic carbon in a eutrophic lake; dynamics,biodegradability and origin

The seasonal and spatial changes in dissolved organic carbon (DOC) in Lake Kasumigaura, a shallow, eutrophic lake, were analyzed and the lability of DOC was tested by long-term incubations. There was a nearly 1 mgCl^–1 downstream increase in refractory DOC in the lake; at the center it fluctuated little seasonally. The characteristic UV-absorbance: DOC ratios were determined for samples from the influent rivers (pedogenic: used interchangeably with allochthonous) and outdoor experimental ponds (autochthonous) during incubations. These ratios were then used to calculate the proportion of total measured lake water DOC in each of four components: pedogenic-refractory (PR), pedogenic-labile (PL), autochthonous-refractory (AR) and autochthonous-labile (AL). PR was uniform (around 1.5 mgCl^–1) or diminished very slightly over time. AR increased from nearly zero at the station closest to an influent river to 1 mgCl^–1 at the lake center. PL declined downstream from 0.3 mgCl^–1 to zero. AL was virtually constant at 0.8 mgCl^–1 except at the station closest to the influent river. The constancy of the UV-absorbance: DOC ratio during the biodegradation process was confirmed for Lake Kasumigaura; hence a two-component model (pedogenic-autochthonous) could be applied here without consideration of DOC lability. However, this assumption is not always met for other water bodies, and therefore it should be checked before applying a two-component model elsewhere.     

基于鱼类生物完整性指数的广东鉴江流域环境质量评估

根据鉴江流域21个观测点鱼类调查所收集的数据,结合历史资料的记录,初步构建基于鱼类生物完整性评价的26个初选指标,并根据指标属性分类进行初筛,对10个通过的候选指标进行分布范围、判别能力和Pearson相关性分析,确定了由总的种类数占期望值的百分比、鲤科鱼类占总种类数的百分比、鳑鲏亚科鱼类占总种类数的百分比、耐受性强鱼类占总种类数的百分比和产漂流性卵鱼类占总种类数的百分比共5个主评指标组成的生物完整性指数体系,并用于鉴江流域部分河段的生态健康评价.结果表明,凌江鱼类完整性相对较好,罗江一般,平定水、袂花江和鉴江干流较差,小东江最差;鉴江流域大多数河段的综合健康状态处于较差状态,需要对鉴江流域进行生态修复以达到相对健康状态.评价结果与河流受人为干扰的实际情况相吻合,研究构建的评价体系可供周边地区使用和借鉴.     

Oceanography of coastal and riverine waters around Timika, West Central Irian Jaya, Arafura Sea

Oceanographic studies have been carried out in coastal and riverine waters of the area around Timika, West Papua in November 1999, March–April, July and November 2000. The temperature of the seawater along the coast is around 28 °C in winter (November 99), rising to 30.0 °C (November 00). In the open sea, 30 miles off the coast at 40 m water depth, the temperature is >30 °C with no stratification. Water temperature near the coast is consistently lower than in the open sea. This is thought to be due the cooling effect of the land, being densely covered by mangrove forest. In the upper parts of the Kamora, West Tipuka, East Tipuka, Ajkwa, Minajerwi, Mawati and Otakwa Rivers, at salinity zero psu, water temperature varies between 24.6 and 26.2 °C, which is as cold as the temperature in the upwelling Banda Sea to the NW. Some of these rivers are fed by glacial melt water from the high mountains to the east. At mid estuary, warm seawater is found under the cooler river water.Salinity near this coast varied between 24 and 30, and offshore salinity was 31–33 with no stratification. Inshore surface waters were turbid (11–14 ntu), and near bottom waters were generally much more turbid from river sediment supply and tidal resuspension. The Ajkwa River estuary has the highest turbidity (750 ntu) at zero salinity. Offshore waters were very clear (5.0–6.0 ntu), and there was no increase in turbidity near the bottom.     

Modification of Pantle–Buck Technique for Assessing Watercourse Pollution Based on Macrobenthos Quality Characteristics

A new index is proposed for water quality assessment in rivers and creeks. The index is similar to the Pantle–Buck saprobity index, but is based on qualitative characteristics and uses macrobenthos families (rarely genera), for which original values of saprobity and indicator weight are given. Data collected at 245 watercourses in the central European Russia are used to study the correlation of the new index with the anthropogenic load onto watercourses, as well as with the watercourse type and size and the type of substrate. The index is shown to be more effective than the Pantle-Buck index modified by Sladecek and the Woodiwiss index and applicable for rapid assessment of watercourse pollution.     

南水北调中线水源地河流大型无脊椎动物物种多样性及其维持机制

生物多样性的形成与维持(即群落构建)一直是生态学研究的重要论题。有关亚热带季风区大型河流生物多样性格局及维持机制的认识仍十分有限。以汉江上游(南水北调中线水源地)为研究区域,以大型无脊椎动物为研究对象,系统开展群落多样性时空格局及其维持机制的研究。于2015—2017年间共采集到大型无脊椎动物333个分类单元,隶属6门10纲25目110科279属,包括水生昆虫278种(83.5%),环节动物门25种(7.5%),软体动物门19种(5.7%),软甲纲7种以及其它动物4种。物种多样性在时间和空间尺度上差异显著:时间上,春季物种数最多(227种),夏季(140种)、秋季(141种)和冬季(144种)较少;空间上,自然河流金水河物种数最多(179种),而金钱河(163种)、月河(149种)、淇河(140种)和泗河(112种)等人类干扰河流相对较少。db-RDA分析表明,尽管不同季节所筛选出的关键因子有所差异,但环境因子和空间因子均显著影响着大型无脊椎动物的群落结构。变差分解分析显示,环境过滤是流域内大型无脊椎动物群落多样性维持的主导因素,而空间过程(扩散限制)则起着次要的作用。本研究对南水北调...